G. F. Atkinson'
and John H. Shaw University of Waterloo Waterloo, Ontario Canada
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Apparatus for Electrodeposition Experiments
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Faced with the need to enable sizeable classes to perform replicate electrodepositions of copper and lead from brass samples, we have investigated alternatives to the use of commercial instruments such as the Sargent-Slomin Electrolytic Analyzer (E. H. Sargent & Co., Chicago) which supplies two working stations at a cost of $750. Our first decision was to modularize our equipment, using conventional magnetic stirrers and stationary electrodes. The problem of supporting and positioning the deposition electrodes was then taken up, and the design illustrated was developed. The assembly shown in the figure consists of a strip of - i n acrylic sheet slotted on the underside to position the beaker rim, and provided with phosphorbronze springs to grip the electrode stems and make the electrical contact. The leadwires are fed through a length of diameter stainless steel tubing which is threaded into the acrylic block a t one end, and welded to a flat plate hearing bindink posts on a/,-in. centers at the other. This design allows easy access to the beaker during an experiment and facilitates the attachment of the cell head to the rod on a laboratory jack for height adjustment, which permits the removal of the electrodes while washing them off a t the end of a run rather than the more cumbersome siphoning and replacement of electrolyte with water. We suggest that the stems of electrodes used in these devices be carefully given a slight flat at the point 'To whom inquiries should be addressed.
of support to remove any tendency to rotate in the holder and thus short-circuit or dislodge plated material by bumping the beaker. By using these cell heads in conjunction with magnetic stirrers, lab jacks, and a modular power supply with built-in meters and current-limiting circuitry, we have provided three working stations at a cost more than $100 below the two-station commercially-available unit. If bench space is not a t a premium, each cell may be powered by a Heathkit battery eliminator at a still greater saving in cost. A secondary benefit of this scheme is the availability of the separate components for other use a t times of the year when the experiment is not set up. I t should be noted that we are using this equipment . as well as a commercially-built electrodeposition unit, so students are not being deprived of the opportunity to see how the latter operates.
Cell cover with electrical connecfion A, po3itioning slots for beaker; 8, phogphor-bronze springs; C, binding posh; D, electrode stem positioning holes.
Volume 46, Number 6 , June 1969
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387
